Acta Materialia最新文献

{"title":"Multi-scale structural analysis of swift heavy ion-irradiated ZrO2 and HfO2","authors":"Alexandre P. Solomon ,&nbsp;Eric C. O’Quinn ,&nbsp;Cale C. Overstreet ,&nbsp;Pascal Simon ,&nbsp;Christina Trautmann ,&nbsp;Changyong Park ,&nbsp;David Sprouster ,&nbsp;Gianguido Baldinozzi ,&nbsp;Maik K. Lang","doi":"10.1016/j.actamat.2026.121926","DOIUrl":"10.1016/j.actamat.2026.121926","url":null,"abstract":"<div><div>The radiation-induced monoclinic-to-tetragonal phase transition in ZrO₂ and HfO₂ has been the subject of many investigations, but the transformation pathways and underlying structural mechanisms are still not well understood. In this study, microcrystalline powder samples of ZrO₂ and HfO₂ were irradiated with 946 MeV and 1470 MeV Au ions to a wide fluence range up to 3 × 10¹³ ions/cm². To characterize beam-induced structural modifications across all spatial length scales, complementary experimental techniques such as synchrotron X-ray diffraction and spallation neutron total scattering were used. The phase evolution of the tetragonal polymorph with increasing ion fluence is accurately described by a heterogeneous track-overlap model that incorporates both direct- and double-impact processes. These damage accumulation processes are an expression of a core-shell ion track morphology that depends on irradiation conditions and target material. Neutron pair distribution function analysis revealed that ion-beam-induced tetragonal ZrO₂ is merely a configurational average of short-range orthorhombic (<em>Pbcn</em>) domains stabilized by a dense network of domain walls. This knowledge is critical for a better understanding of how crystalline-to-crystalline phase transformations proceed at the atomic scale under extreme conditions.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"306 ","pages":"Article 121926"},"PeriodicalIF":9.3,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of strain rate and c-axis orientation on microscale α-Ti compression: From kink bands to twinning","authors":"Kamila Hamulka ,&nbsp;Tijmen Vermeij ,&nbsp;Amit Sharma ,&nbsp;Renato Pero ,&nbsp;Johann Michler ,&nbsp;Xavier Maeder","doi":"10.1016/j.actamat.2026.121923","DOIUrl":"10.1016/j.actamat.2026.121923","url":null,"abstract":"<div><div>The plastic deformation behavior of high-purity alpha-titanium (α-Ti) single crystals is investigated through micropillar compression experiments over a wide range of strain rates <span><math><mrow><mo>(</mo><mrow><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>3</mn><mspace></mspace></mrow></msup><mtext>to</mtext><mspace></mspace><msup><mrow><mn>10</mn></mrow><mn>3</mn></msup><mspace></mspace><msup><mrow><mi>s</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow><mo>)</mo></mrow></math></span> at room temperature. For <em>c</em> - axis compression, where prismatic slip is geometrically unfavorable, two distinct deformation regimes emerge. At low to intermediate strain rates <span><math><mrow><mo>(</mo><mover><mrow><mi>ε</mi></mrow><mi>˙</mi></mover><mo>&lt;</mo><msup><mrow><mn>10</mn></mrow><mn>2</mn></msup><mspace></mspace><msup><mrow><mi>s</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup><mo>)</mo></mrow></math></span> plasticity is governed by a non-classical kink band-type mechanism. Deformation is accommodated within broad, localized bands exhibiting significant continuous lattice rotation and internal <span><math><mrow><mo>〈</mo><mrow><mi>c</mi><mo>+</mo><mi>a</mi></mrow><mo>〉</mo><mspace></mspace></mrow></math></span> dislocation structures. These bands lack discrete slip traces and show features distinct from conventional slip or twinning. At higher strain rates <span><math><mrow><mo>(</mo><mrow><mover><mrow><mi>ε</mi></mrow><mi>˙</mi></mover><mo>≥</mo><msup><mrow><mn>10</mn></mrow><mn>2</mn></msup><mspace></mspace><msup><mrow><mi>s</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow><mo>)</mo></mrow></math></span> a transition to deformation twinning is observed, characterized by exhaustive <span><math><mrow><mrow><mo>{</mo><mrow><mn>11</mn><mover><mn>2</mn><mo>¯</mo></mover><mn>2</mn></mrow><mo>}</mo></mrow><mrow><mo>〈</mo><mrow><mover><mn>1</mn><mo>¯</mo></mover><mover><mn>1</mn><mo>¯</mo></mover><mn>23</mn></mrow><mo>〉</mo></mrow></mrow></math></span> twinning and twin-twin interactions. This shift in deformation mode coincides with a notable increase in flow stress. In contrast, for compression perpendicular to the <em>c</em> - axis, plastic deformation is consistently accommodated by prismatic <span><math><mrow><mrow><mo>{</mo><mrow><mn>10</mn><mover><mn>1</mn><mo>¯</mo></mover><mn>0</mn></mrow><mo>}</mo></mrow><mrow><mo>〈</mo><mrow><mn>11</mn><mover><mn>2</mn><mo>¯</mo></mover><mn>0</mn></mrow><mo>〉</mo></mrow></mrow></math></span> slip across the entire range of strain rates, without showing any evidence of twinning or kink band formation. Additionally, the flow stress is significantly (7x) lower than that under <em>c</em> - axis loading. This work provides direct experimental evidence of strain rate-induced transitions in deformation mechanisms of α-Ti at the microscale.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"306 ","pages":"Article 121923"},"PeriodicalIF":9.3,"publicationDate":"2026-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heterogeneous-phase-mediated plastic deformation and phase transformation of titanium upon deviatoric stress","authors":"Bo Li ,&nbsp;Chenhui Hu ,&nbsp;Kaiyuan Shi ,&nbsp;Lei Su ,&nbsp;Yizhe Cao ,&nbsp;Huiying Liu ,&nbsp;Dongxu Hui ,&nbsp;Shaodi Wang ,&nbsp;Chuanwei Fan ,&nbsp;Katsuyoshi Kondoh ,&nbsp;Xin Zhang ,&nbsp;Shengyin Zhou ,&nbsp;Shufeng Li","doi":"10.1016/j.actamat.2026.121909","DOIUrl":"10.1016/j.actamat.2026.121909","url":null,"abstract":"<div><div>Deviatoric stress and microstructural imperfections are considered the main reasons for the promotion of phase transformation (PT) of metals at high pressure. However, structural heterogeneity induced by secondary phases will pose challenges for understanding the high-pressure deformation and PT of metallic composites. For instance, anomalies related to kinetic suppression were observed in the forward (α→ω) and reverse (ω→α) transformation of α-Ti confined by TiB upon nonhydrostatic pressure. Here, static/dynamic diamond anvil cells and synchrotron X-ray diffraction were utilized to panoramically resolve the dislocation evolution in plastic flow deformation and strain-induced PT of Ti-TiB microcomposite. Diffraction peak profile analysis reveals a decrease in dislocation density of confined α-Ti from plastic flow (1×10¹⁶ m⁻²) to strain-induced PT (6.7×10¹⁵ m⁻²), accompanied with the activation of ∼60% &lt;a&gt; slip systems and a varying combination of &lt;c&gt; and &lt;c+a&gt;. Long-range internal stress at Ti/TiB interface increases quasi-linearly to a maximum accounting for ∼17% of total pressure as the nonhydrostatic pressure increases. It probably indicates the key role of heterogeneous-stress-partition in lowering local stress required for the dislocation-mediated growth of critical ω nucleus. Furthermore, analytical results demonstrate the kinetics of PT of Ti and Ti-TiB could be well unified through the Levitas’s strain-induced kinetic equation, though their accumulated plastic strain differs by a factor of ∼3. This work shed light on the role of heterogeneous phase in high-pressure deformation and PT of metals and display promising applications such as manipulation of pressure-related strength/plasticity and PT kinetics of metals via compatible second-phases.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"306 ","pages":"Article 121909"},"PeriodicalIF":9.3,"publicationDate":"2026-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dopant-dependent pore formation in plastic Ag2Se contributing to ultrahigh thermoelectric performance","authors":"Zhentao Guo ,&nbsp;Lankun Wang ,&nbsp;Zihou Xu ,&nbsp;Yu-Ke Zhu ,&nbsp;Xingyan Dong ,&nbsp;Hao Wu ,&nbsp;Fengkai Guo ,&nbsp;Wei Cai ,&nbsp;Jiehe Sui ,&nbsp;Zihang Liu","doi":"10.1016/j.actamat.2026.121917","DOIUrl":"10.1016/j.actamat.2026.121917","url":null,"abstract":"<div><div>Porous bulk materials demonstrate a diverse range of functional applications, including catalysis, energy storage, and thermal management. However, the available synthesis methods are not applicable or complex for a variety of materials. In this work, we discovered that minor doping induced a compromise between plasticity and porosity in Ag₂Se bulk materials, enabling the general synthesis of high-performance porous thermoelectric materials. Li/Na/Br doping reduces plasticity, increasing initial pores and suppressing plastic flow to yield grain-refined porous structures. Conversely, Cu/In/Te doping sustains/enhances plasticity, resulting in dense microstructures comparable to undoped Ag₂Se. Moreover, Li doping reduces carrier concentration (<em>n</em>_H) through cation vacancy regulation, demonstrated by density functional theory (DFT) calculations. Benefiting from the reduced electrical thermal conductivity from lowered <em>n</em>_H and diminished lattice thermal conductivity via hierarchical phonon scattering, ultralow thermal conductivity of 0.63 W·m^-1·K^-1 is realized at 300 K for Ag_1.95Li_0.05Se. Combined with maintained high power factors, the Ag_1.95Li_0.05Se achieves an exceptionally high average <em>ZT</em> of 0.93 between 300 and 383 K. Our findings have fundamentally changed the synthesis process for thermoelectric materials, providing a new perspective on the role of doping-induced microstructural modulation and advancing the design of high-performance porous materials.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"306 ","pages":"Article 121917"},"PeriodicalIF":9.3,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oxidation-induced dissolution initiated from semicoherent δ/matrix interface in Inconel 718 superalloy","authors":"Mingzhe Liu ,&nbsp;Xiaojia Wei ,&nbsp;Yunsong Zhao ,&nbsp;Yanhui Chen ,&nbsp;Liwei Cao ,&nbsp;Weiyi Wu ,&nbsp;Xueqiao Li ,&nbsp;Xingfei Pei ,&nbsp;Ang Li ,&nbsp;Lihua Wang ,&nbsp;Xiaodong Han","doi":"10.1016/j.actamat.2026.121924","DOIUrl":"10.1016/j.actamat.2026.121924","url":null,"abstract":"<div><div>Interfaces such as grain boundaries, phase interfaces, precipitate/matrix interfaces and defect/matrix interfaces disrupt long-range atomic arrangement order and elemental distribution continuity. Reinforcing interfaces to enhance their mechanical performance and corrosion resistance is essential for their application in harsh service environments. The interfaces of numerous alloys have been mechanically enhanced by processing or element control. In most instances, interfaces still serve as initial oxidation sites, degrading the overall properties of the alloy. Hence, improving the corrosion resistance of an interface is still necessary to improve their applicability. In particular, for Inconel 718 alloys, a primary failure scenario is corrosion-induced failure in harsh working environments, such as high-temperature coupled oxygen-rich environments. This type of failure is normally considered to be initiated from the high quantity of δ/matrix phase interfaces. However, the understanding of the oxidation mechanisms and dynamics initiated at the δ/matrix phase interface is still limited because of a lack of <em>in situ</em> high spatial resolution studies. Here, the thermal oxidation behavior of the semicoherent δ/matrix interface in the Inconel 718 alloy is studied via aberration-corrected environmental transmission electron microscopy (ETEM). The dynamic evolution of the two-phase interface down to the atomic scale is revealed via <em>in situ</em> experiments. Preferential oxidation from the δ/matrix phase interface occurs at relatively low temperatures. Moreover, selective oxidation induces mutual mass transfer on both sides of the interface. Combined with the findings from molecular dynamics simulations, the results confirm that the semicoherent δ/matrix boundary exhibits a large lattice misfit and high energy, which ultimately facilitates the preferential oxidation of the interface. This work provides direct experimental data on the stress corrosion of superalloys and offers reference data for material design and improvement.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"306 ","pages":"Article 121924"},"PeriodicalIF":9.3,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"3D perspective on cavity-guided dendritic array evolution in single-crystal superalloys: A novel vectorized analytical model","authors":"Haoyu Zhou ,&nbsp;Congjiang Zhang ,&nbsp;Chuanxin Shi ,&nbsp;Hongbin Yu ,&nbsp;Hongda Kang ,&nbsp;Yufeng Yang ,&nbsp;Weili Ren ,&nbsp;Biao Ding ,&nbsp;Tianxiang Zheng ,&nbsp;Yunbo Zhong ,&nbsp;Ang Zhang ,&nbsp;Peter K. Liaw","doi":"10.1016/j.actamat.2026.121921","DOIUrl":"10.1016/j.actamat.2026.121921","url":null,"abstract":"<div><div>A fundamental mechanism of the dendritic array evolution during the directional solidification (DS) of modern turbine blades remains inadequately understood. This is largely due to the geometric constraints imposed by the complex shell mold, which defines both the external airfoil and internal cooling passages. This work focuses on establishing a model that integrates spiral geometry parameters, temperature gradients, and crystallographic orientations by developing a vectorized analytical framework in 3D Cartesian coordinates. It could quantitatively describe anisotropic dendritic growth kinetics. The results show that temperature gradients along the direction of secondary branches govern the dendrite transformation, leading to the formation of linear dendritic arrays in transverse cross-sections. During the spiral rise, the linear dendritic arrays undergo dynamic directional changes, and newly formed dendrites replace original ones through orientation competition and spatial dominance. The rearrangement of dendritic arrays is orthogonal to the original arrangement. This study clarifies the evolution behavior of dendritic arrays in complex cavities and provides a theoretical foundation for controlling solidification microstructures in single-crystal (SC) blades.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"306 ","pages":"Article 121921"},"PeriodicalIF":9.3,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145947510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temperature dependence of the interface energy in Al-Cu alloys from first-principles and phonon calculations","authors":"Wei Shao ,&nbsp;Yi Yang ,&nbsp;Jan S. Wróbel ,&nbsp;Javier LLorca","doi":"10.1016/j.actamat.2026.121925","DOIUrl":"10.1016/j.actamat.2026.121925","url":null,"abstract":"<div><div>The interface free energies at A/B (<em>A</em>=Al and θ′′, <em>B</em>=θ′′ and θ′) interfaces were determined as a function of temperature by means of first-principles and phonon calculations within the framework of harmonic and quasi-harmonic approximations. The interface free energies of five interfaces - Al(001)||θ′′(001), Al(001)||θ′(001), θ′′(001)||θ′(001), Al(010)||θ′′(010) and Al(010)||θ′(010) - decreased with increasing temperature as a result of the vibrational entropic contribution. Furthermore, it was found that effect of thermal expansion on the interface free energy is negligible for the Al(001)||θ′′(001), Al(001)||θ′(001) and Al(010)||θ′(010) interface, while it will lead to an increase or decrease in interface free energy of Al(010)||θ′′(010) or θ′′(001)||θ′(001), respectively. The differences in the temperature dependence of interfacial free energies among the five interfaces can be attributed to variations in stretching stiffness resulting from changes in bond lengths and the proportion of Al-Al and Al-Cu bonds in each interface. This study provides atomistic insights into temperature-dependent interfacial free energy and motivates future work extending this approach to more complex systems.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"306 ","pages":"Article 121925"},"PeriodicalIF":9.3,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145947508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of the thermodynamics, kinetics and crystallization sequence of Ni–Nb–P-based bulk metallic glass-forming alloys","authors":"Lucas M. Ruschel ,&nbsp;Bastian Adam ,&nbsp;Oliver Gross ,&nbsp;Maximilian Frey ,&nbsp;Nico Neuber ,&nbsp;Fan Yang ,&nbsp;Ralf Busch","doi":"10.1016/j.actamat.2026.121918","DOIUrl":"10.1016/j.actamat.2026.121918","url":null,"abstract":"<div><div>This study investigates the glass-forming ability of Ni–Nb–P-based bulk metallic alloys through a systematic analysis of their thermodynamic, kinetic, and crystallization behavior. Differential scanning calorimetry, viscosity measurements, and in-situ synchrotron X-ray diffraction were employed to examine three compositions: Ni₆₂Nb₃₈, Ni_59.2Nb_38.8P₂ and Ni_59.2Nb_33.8Ta₅P₂. While all alloys exhibit a high thermodynamic driving force for crystallization, the phosphorus- and tantalum-containing variants demonstrate significantly improved glass-forming ability. This improvement is linked to increased viscosity and suppression of primary crystallization. In particular, the addition of phosphorus promotes the formation of a phosphorus-rich intermetallic phase that requires long-range diffusion, delaying crystallization. The combined kinetic slowdown and delayed phase formation sufficiently retard crystallization, allowing fully amorphous samples up to 6 mm in diameter to be produced, compared to 2 mm for binary Ni–Nb. These findings highlight how judicious micro-alloying can enhance glass-forming ability through kinetic control of the crystallization pathway.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"306 ","pages":"Article 121918"},"PeriodicalIF":9.3,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First phase diagram of dislocation loops achieved through an innovative analytical framework","authors":"Junjie Cao ,&nbsp;Liping Guo ,&nbsp;Yiheng Chen ,&nbsp;Congxiao Liu ,&nbsp;Rui Yan ,&nbsp;Hongtai Luo","doi":"10.1016/j.actamat.2026.121916","DOIUrl":"10.1016/j.actamat.2026.121916","url":null,"abstract":"<div><div>An analytical model is presented that characterizes the evolution of irradiation-induced dislocation loops in ferritic/martensitic (F/M) steels. The model establishes quantitative relationships among microstructural changes, irradiation conditions, and mechanical properties, predicting both dislocation loop behavior and irradiation hardening. Analysis indicates that the density of a/2&lt;111&gt; loops decreases with increasing temperature over 250 °C, whereas a&lt;100&gt; loops peak at approximately 450 °C before declining. Both loop types exhibit saturation at high irradiation doses, and their size distributions are well described by a log-normal function. An L-shaped phase diagram identifies a transition region between 350-400 °C, reflecting a shift in the dominant dislocation loop type. The model’s explicit functional relationships provide a basis for optimizing the design and performance of F/M steels in advanced nuclear systems, potentially contributing to enhanced irradiation resistance and material reliability.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"306 ","pages":"Article 121916"},"PeriodicalIF":9.3,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Significantly enhanced heat transport capability across nitrogen-doped graphene/metal interface through lattice substitution induced inelastic phonon scattering","authors":"Haoyu Huang ,&nbsp;Kunming Yang ,&nbsp;Song Hu ,&nbsp;Boan Zhong ,&nbsp;Yu Wang ,&nbsp;Qi Zhang ,&nbsp;Jiamiao Ni ,&nbsp;Yufei Liu ,&nbsp;Xiaokun Gu ,&nbsp;Yue Liu ,&nbsp;Tongxiang Fan","doi":"10.1016/j.actamat.2026.121908","DOIUrl":"10.1016/j.actamat.2026.121908","url":null,"abstract":"<div><div>Interface defects play a critical role in heat transport across metal/nonmetal interfaces, constructing defect-controllable interfaces and investigating phonon behaviors related heat transport mechanisms may facilitate the design of advanced devices with enhanced interfacial heat transport performance. In this work, the nitrogen-doped graphene (marked as N-Gr) with gradient defect density was synthesized on copper (Cu) via vapor deposition process. Compared to other methods, such as plasma treatment and ion beam bombardment, defect density of N-Gr/Cu interface was precisely modified and quantified through nitrogen doping process. Based on microstructure characterizations, including time-domain thermorefletance (TDTR) measurements, first-principles density functional theory (DFT) calculations and temperature-dependent non-equilibrium molecular dynamics (NEMD) simulations, the influence of two types of N doping atoms (substitutional N and interstitial N) on interfacial phonon transport behaviors were identified. The authors believe that the substitutional N atoms within Gr lattice may activate inelastic phonon scattering with high-frequency to low-frequency phonons, which are providing additional interfacial heat transport channels with significantly enhanced thermal boundary conductance (<em>G</em>) of the Al/N-Gr/Cu interface from ∼31 to ∼48 MW/m²·K. However, the interstitial N atoms within Gr interlayers impede low-frequency phonons from transporting across Al/N-Gr/Cu interfaces, thus leading to a reduced <em>G</em>. These two types of N atoms form a critical effect in dominating heat transport mechanisms at Al/N-Gr/Cu interfaces. The present findings suggest that lattice substitution may be an effective approach to soften high-frequency phonons and promote heat transport across metal/nonmetal interfaces.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"306 ","pages":"Article 121908"},"PeriodicalIF":9.3,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146034990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}